Title:
COMPUTER CAPABLE OF AUTOMATIC BANDWIDTH CONFIGURATION ACCORDING TO I/O EXPANSION CARD TYPE
Kind Code:
A1


Abstract:
A computer capable of automatic bandwidth configuration according to I/O expansion card (e.g., PCI-Express expansion card) type is provided. A motherboard of the computer includes an I/O expansion slot, a chipset, and a configuration setting circuit. When the I/O expansion slot supports different types of I/O expansion cards having multiple interface card slot combinations, a corresponding bandwidth configuration message is generated on the I/O expansion card. The bandwidth configuration message is used to indicate the type of the I/O expansion card that is being used and thereby control the configuration setting circuit to adjust the bandwidth configuration in the chipset.



Inventors:
Ji, Hai-yi (Shanghai City, CN)
Liu, Shih-hao (Taipei City, TW)
Application Number:
12/328486
Publication Date:
04/22/2010
Filing Date:
12/04/2008
Assignee:
Inventec Corporation (Taipei City, TW)
Primary Class:
International Classes:
G06F13/00
View Patent Images:



Primary Examiner:
KNOLL, CLIFFORD H
Attorney, Agent or Firm:
J C PATENTS (4 VENTURE, SUITE 250, IRVINE, CA, 92618, US)
Claims:
What is claimed is:

1. A computer comprising: an I/O expansion card comprising: an interface card slot for selectively accepting an interface card; and a configuration message generator configured to provide a bandwidth configuration message corresponding to the interface card slot; and a motherboard comprising: an I/O expansion slot for accepting the I/O expansion card; a chipset coupled to the I/O expansion slot so as to be connected to the interface card slot of the I/O expansion card through the I/O expansion slot; and a configuration setting circuit coupled to the chipset and the I/O expansion slot, the configuration setting circuit configured to obtain the bandwidth configuration message through the I/O expansion slot and set an internal interface-card-bandwidth configuration in the chipset based on the bandwidth configuration message.

2. The computer according to claim 1, wherein the chipset is a north bridge chip.

3. The computer according to claim 1, wherein the interface card slot is a PCI-Express slot, and the internal interface-card-bandwidth configuration set by the configuration setting circuit is a PCI-Express bandwidth configuration in the chipset.

4. The computer according to claim 1, wherein the configuration setting circuit is coupled to configuration setting pins of the chipset, and the configuration setting circuit comprises: a default digital code generating circuit configured to generate a default digital code; and an adjustment circuit coupled to the default digital code generating circuit, the configuration setting pins of the chipset and the I/O expansion slot, the adjustment circuit configured to adjust the default digital code provided by the default digital code generating circuit according to the bandwidth configuration message and output the adjusted default digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

5. The computer according to claim 1, wherein the configuration setting circuit is coupled to configuration setting pins of the chipset, the configuration setting circuit comprises a complex programmable logic device coupled to the configuration setting pins of the chipset and the I/O expansion slot, and the complex programmable logic device is configured to generate a corresponding digital code according to the bandwidth configuration message and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

6. The computer according to claim 1, wherein the configuration setting circuit is coupled to configuration setting pins of the chipset, the configuration setting circuit comprises an encoding circuit coupled to the configuration setting pins of the chipset and the I/O expansion slot, and the encoding circuit is configured to generate a corresponding digital code by encoding the bandwidth configuration message and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

7. The computer according to claim 1, wherein the configuration setting circuit is coupled to configuration setting pins of the chipset, the configuration setting circuit comprises a micro processor coupled to the configuration setting pins of the chipset and the I/O expansion slot, and the micro processor is configured to look up a digital code corresponding to the bandwidth configuration message in a mapping table and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of China application serial no. 200810169744.0, filed on Oct. 16, 2008. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a computer, and more particularly, to a computer capable of automatic bandwidth configuration according to a type of an I/O expansion card.

2. Description of Related Art

In the interior of a known computer platform, the central processing unit (CPU) and various hardware components are typically interconnected by a bus to transmit data therebetween. Following continuous advancing of hardware design, various high speed bus design concepts have been continuously developed to meet the need of high speed transmission of huge quantity of data.

Various interface cards have been used to expand functions of the computer platform. By plugging the interface cards into I/O expansion slots of the computer, the interface cards can provide the computer user with desired services. However, the number of the I/O expansion slots of the computer platform is often limited by the space and cost. An I/O expansion card is used to provide a plurality of interface card slots for accepting multiple interface cards and thus serves the purpose of increasing the I/O expansion slots number. When multiple interface cards are plugged into the interface card slots of the I/O expansion card and therefore coupled to the I/O expansion slot through the I/O expansion card, the bandwidth of the I/O expansion slot is shared by the multiple interface cards.

FIG. 1 illustrates a PCI-Express interface bus architecture for a computer in which a chipset CS1 provides multiple I/O expansion slots Slot0˜Slot2. In the existing design, the bandwidth configurations of the I/O expansion slots Slot0˜Slot2 are determined based on input signals of configuration setting pins of the chipset CS1. Therefore, the bandwidth configurations of the I/O expansion slots Slot0˜Slot2 are fixed, and the bandwidth configurations of the multiple interface card slots of the I/O expansion cards are also fixed. However, it is impossible to know the bandwidth configurations of the I/O expansion cards in advance.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a computer including an I/O expansion card and a motherboard, which can automatically adjust bandwidth configuration based on bandwidth requirements of the I/O expansion card.

The present invention provides a computer including an I/O expansion card and a motherboard. The I/O expansion card includes an interface card slot and a configuration message generator. The interface card slot is used to selectively accept an interface card. The configuration message generator is used to provide a bandwidth configuration message corresponding to the interface card slot. The motherboard includes an I/O expansion slot, a chipset, and a configuration setting circuit. The I/O expansion slot is used to accept the I/O expansion card. The chipset is coupled to the I/O expansion slot so as to be connected to the interface card slot of the I/O expansion card through the I/O expansion slot. The configuration setting circuit is coupled to the chipset and the I/O expansion slot. The configuration setting circuit is used to obtain the bandwidth configuration message through the I/O expansion slot and set an internal interface-card-bandwidth configuration in the chipset based on the bandwidth configuration message.

According to one embodiment of the present invention, the interface card slot is a PCI-Express slot, and the internal interface-card-bandwidth configuration set by the configuration setting circuit is a PCI-Express bandwidth configuration in the chipset.

According to one embodiment of the present invention, the configuration setting circuit is coupled to configuration setting pins of the chipset. The configuration setting circuit includes a default digital code generating circuit and an adjustment circuit. The default digital code generating circuit is used to generate a default digital code. The adjustment circuit is coupled to the default digital code generating circuit, the configuration setting pins of the chipset and the I/O expansion slot. The adjustment circuit is used to adjust the default digital code provided by the default digital code generating circuit according to the bandwidth configuration message and output the adjusted default digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

According to one embodiment of the present invention, the configuration setting circuit is coupled to configuration setting pins of the chipset. The configuration setting circuit includes a complex programmable logic device (CPLD) coupled to the configuration setting pins of the chipset and the I/O expansion slot. The CPLD is used to generate a corresponding digital code according to the bandwidth configuration message and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

According to one embodiment of the present invention, the configuration setting circuit is coupled to configuration setting pins of the chipset. The configuration setting circuit includes an encoding circuit coupled to the configuration setting pins of the chipset and the I/O expansion slot. The encoding circuit is used to generate a corresponding digital code by encoding the bandwidth configuration message and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

According to one embodiment of the present invention, the configuration setting circuit is coupled to configuration setting pins of the chipset. The configuration setting circuit includes a micro processor coupled to the configuration setting pins of the chipset and the I/O expansion slot. The micro processor is used to look up a digital code corresponding to the bandwidth configuration message and output the digital code to the configuration setting pins of the chipset to set the internal interface-card-bandwidth configuration in the chipset.

The present invention provides a computer including an I/O expansion card and a motherboard. When the I/O expansion slot supports different types of I/O expansion cards having multiple interface card slot combinations, a configuration message generator disposed on the I/O expansion card generates a bandwidth configuration message outputted to the I/O expansion slot according to the type of the interface card that is being used. A configuration setting circuit is coupled to the I/O expansion slot and configuration setting pins of the chipset. The configuration setting circuit receives the bandwidth configuration message, generates a bandwidth configuration signal based on the bandwidth configuration message, and outputs the bandwidth configuration signal to the configuration setting pins of the chipset. The internal interface-card-bandwidth configuration in the chipset can be set based on the bandwidth configuration signal, thereby automatically adjusting the chipset bandwidth configuration to meet the bandwidth requirement of the interface cards plugged into the I/O expansion card.

In order to make the aforementioned and other features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a PCI-Express interface bus architecture of a known computer platform.

FIG. 2 illustrates a diagram depicting an exemplary bandwidth configuration of computer I/O expansion cards according to an embodiment of the present invention.

FIGS. 3A-3B illustrate a structure of the I/O expansion card according to a embodiment of the present invention.

FIG. 4 illustrates a diagram of the configuration setting circuit of the embodiment of the present invention.

FIG. 5A illustrates a diagram of the configuration setting circuit of a second embodiment of the present invention.

FIG. 5B illustrates a diagram of the configuration setting circuit of a third embodiment of the present invention.

FIG. 5C illustrates a diagram of the configuration setting circuit of a fourth embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

Features and advantages of the automatic bandwidth configuration of the I/O expansion card will now be described in junction with preferred embodiments below that are illustrated in the accompanying drawings.

FIG. 2 is a diagram depicting an exemplary bandwidth configuration of computer I/O expansion cards. Referring to FIG. 2, the computer 200 includes an I/O expansion card 210 and a motherboard 250. The I/O expansion card 210 has an interface card slot 220 and a configuration message generator 230. While only one exemplary interface card slot 220 is illustrated in FIG. 2, it is to be understood that the I/O expansion card 210 could have one or more interface card slots. The interface card slot 220 is coupled to an I/O expansion slot IOU1 by a bus BUS1 and is adapted to accept an interface card thereinto. The configuration message generator 230 is coupled to the I/O expansion slot IOU1 and used to generate a bandwidth configuration message SM1 corresponding to the interface card slot 220 for indicating the bandwidth configuration of the interface card slot 220.

The motherboard 250 includes three I/O expansion slots IOU0˜IOU2, a chipset 280, and a configuration setting circuit 270. The I/O expansion slot IOU1 is used to accept the I/O expansion card 210, the I/O expansion slot IOU0 is used to accept an I/O expansion card 211, and the I/O expansion slot IOU2 is used to accept an I/O expansion card 212. As described above, the motherboard 250 can have one or more I/O expansion slots and detail description is only made herein regarding the exemplary I/O expansion slot IOU1. The chipset 280 and the I/O expansion slot IOU1 are coupled by a bus BUS2. The bus BUS1 is coupled to the bus BUS2 through the I/O expansion slot IOU1. The configuration setting circuit 270 is coupled between the chipset 280 and the I/O expansion slot IOU1. The bandwidth configuration message SM1 generated by the configuration message generator 230 is transmitted to the configuration setting circuit 270 through the I/O expansion slot IOU1. The configuration setting circuit 270 generates a bandwidth configuration signal SC transmitted to the chipset 280 in response to the bandwidth configuration message SM1. The bandwidth configuration signal SC is used to set the internal interface-card-bandwidth configuration in the chipset 280.

In the present embodiment, the chipset 280 is a north bridge chip. While the chipset 280 is illustrated as the north bridge chip in the exemplary embodiment, it is to be understood that the chipset 280 could be other chipsets of the similar bus interface. In the present embodiment, the interface card slot 220 is a PCI-Express interface slot and therefore the internal interface-card-bandwidth configuration in the chipset 280 set by the configuration setting circuit 270 is the PCI-Express bandwidth configuration in the chipset 280.

In the present embodiment, configuration setting pins of the chipset 280 have six bits, i.e., PEWIDTH[5..0]. The chipset 280 has thirty-six differential lines which are allocated into three I/O expansion slots IOU0˜IOU2. The bandwidth configuration combinations of the ports of the chipset 280 (i.e., the bandwidth configuration combinations of the I/O expansion slots IOU0˜IOU2) can be flexibly changed. In the present embodiment, the I/O expansion slot IOU2 has two PCIEX2 ports, the I/O expansion slot IOU0 has four PCIEX4 ports, and the I/O expansion slot IOU1 has four PCIEX4 ports, as shown in Table 1. As shown, when different bandwidth configuration signals SC are transmitted to the configuration setting pins PEWIDTH[5..0], the I/O expansion slots IOU0˜IOU2 can be set to have corresponding bandwidth configurations.

TABLE 1
Bandwidth Configuration Setting Table
IOU2IOU0IOU1
PEWIDTH[5 . . . 0]Port1Port2Port3Port4Port5Port6Port7Port8Port9Port10
x2x2x4x4x4x4x4x4x4x4
000000x2x2x4x4x4x4x4x4x4x4
000001x2x2x4x4x4x4x8x4x4
000010x2x2x4x4x4x4x4x4x8
000011x2x2x4x4x4x4x8x8
000100x2x2x8x4x4x4x4x4x4
000101x2x2x8x4x4x8x4x4
000110x2x2x8x4x4x4x4x8
000111x2x2x8x4x4x8x8
001000x2x2x4x4x8x4x4x4x4
001001x2x2x4x4x8x8x4x4
001010x2x2x4x4x8x4x4x8
001011x2x2x4x4x8x8x8
001100x2x2x8x8x4x4x4x4
001101x2x2x8x8x8x4x4
001110x2x2x8x8x4x4x8
001111x2x2x8x8x8x8
010000x2x2X16x4x4x4x4
010001x2x2X16x8x4x4
010010x2x2X16x4x4x8
010011x2x2X16x8x8
010100X2x2x4x4x4x4x16
010101X2x2x8x4x4x16
010110X2x2x4x4x8x16
010111X2x2x8x8x16
011000X2x2X16x16
011001X2x2X16x16
011010X2x2X16x16
011011X2x2X16x16
011100Wait-on-BIOS
011101Wait-on-BIOS
011110Wait-on-BIOS
011111Wait-on-BIOS
100000x4x4x4x4x4x4x4x4x4
100001x4x4x4x4x4x8x4x4
100010x4x4x4x4x4x4x4x8
100011x4x4x4x4x4x8x8
100100x4x8x4x4x4x4x4x4
100101x4x8x4x4x8x4x4
100110x4x8x4x4x4x4x8
100111x4x8x4x4x8x8
101000x4x4x4x8x4x4x4x4
101001x4x4x4x8x8x4x4
101010x4x4x4x8x4x4x8
101011x4x4x4x8x8x8
101100x4x8x8x4x4x4x4
101101x4x8x8x8x4x4
101110x4x8x8x4x4x8
101111x4x8x8x8x8
110000x4X16x4x4x4x4
110001x4X16x8x4x4
110010x4X16x4x4x8
110011x4X16x8x8
110100x4x4x4x4x4x16
110101x4x8x4x4x16
110110x4x4x4x8x16
110111x4x8x8x16
111000x4X16x16
111001x4X16x16
111010x4X16x16
111011x4X16x16

The present embodiment is discussed taking the I/O expansion slot IOU1 as an example and it should be understood that the I/O expansion slot IOU0 or IOU2 can be configured in a similar way as described. It is assumed that the I/O expansion slot IOU1 supports two types of I/O expansion cards, i.e., the I/O expansion card RC0 shown in FIG. 3A and the I/O expansion card RC1 shown in FIG. 3B. Referring to FIG. 3A, the I/O expansion card RC0 includes a PCIEX16 interface card slot AD0 and a configuration message generator CM1 having a pull-down resistor R1. One end of the pull-down resistor R1 is coupled to a reference voltage VSS1 to generate a bandwidth configuration message SM1 (low voltage level) for the interface card slot AD0. Referring to FIG. 3B, the I/O expansion card RC1 includes two PCIEX8 interface card slots AD1˜AD2 and a configuration message generator CM2 having a pull-up resistor R2. One end of the pull-up resistor R2 is coupled to a voltage source V1 to generate a bandwidth configuration message SM1 (high voltage level) for the interface card slots AD1˜AD2.

FIG. 4 illustrates a circuit diagram of the configuration setting circuit 270. The configuration setting circuit 270 includes a default digital code generating circuit 410 and an adjustment circuit 450. It is noted that FIG. 4 does not show the entire circuit of the default digital code generating circuit 410, but only shows a voltage source V2 and resistors R10˜R15 in which the resistor R12 is a pull-down resistor and the resistors R10˜R11 and R13˜R15 are pull-up resistors. The default digital code generating circuit 410 can output a default code “111011” to the adjustment circuit 450 under the operation of the pull-down resistor R12 and the pull-up resistors R10˜R11 and R13˜R15. When the I/O expansion card RC0 (or RC1) is plugged into the I/O expansion slot IOU1, the adjustment circuit 450 can adjust the default code “111011” supplied from the default digital code generating circuit 410 according to the bandwidth configuration message SM1 generated by the configuration message generator CM1 (or CM2), and output the adjusted default code to the configuration setting pins PEWIDTH[5..0] of the chipset 280 to set an internal PCI-Express bandwidth configuration in the chipset 280. According to settings of Table 1, when the I/O expansion card RC0 is plugged into the I/O expansion slot IOU1, the adjustment circuit 450 does not adjust the default code “111011” according to the bandwidth configuration message SM1 generated by the configuration message generator CM1, but directly transmits the default code “111011” to the configuration setting pins PEWIDTH[5..0]. When the I/O expansion card RC1 is plugged into the I/O expansion slot IOU1, the adjustment circuit 450 adjusts the default code “111011” supplied from the default digital code generating circuit 410 to code “110011” according to the bandwidth configuration message SM1 generated by the configuration message generator CM2, and outputs the adjusted default code “110011” to the configuration setting pins PEWIDTH[5..0] of the chipset 280. As such, an adaptive bandwidth allocation can be achieved for the I/O expansion card RC0 or RC1.

FIG. 4 does not show the entire circuit of the adjustment circuit 450, but only shows a metal-oxide-semiconductor field-effect transistor (MOSFET) Q1, a reference voltage VSS2 and a resistor R3. While the MOSFET Q1 is used in the present exemplary embodiment, it should be understood that other transistors, electronic components and circuits having the same function can also be employed in alternative embodiments. The gate of the MOSFET Q1 is coupled to the I/O expansion slot IOU1. The configuration message generator 230 (corresponding to the configuration message generator CM1 in FIG. 3A or configuration message generator CM2 in FIG. 3B) generates a bandwidth configuration message SM1 which is transmitted to the gate of the MOSFET Q1 through the I/O expansion slot IOU1. The source of the MOSFET Q1 is coupled to the reference voltage VSS2 (low voltage level) through the pull-down resistor R3. The drain of the MOSFET Q1 is coupled to the voltage source V2 (high voltage level) through the pull-up resistor R13.

When the I/O expansion card RC0 is plugged into the I/O expansion slot IOU1, the configuration message generator CM1 of the I/O expansion card RC0 generates a low voltage level bandwidth configuration message SM1 such that the MOSFET Q1 is turned off and the drain voltage of the MOSFET Q1 is in a high level. The adjustment circuit 450 outputs the adjusted digital code DG (the default code “111011” at this time) as a bandwidth configuration signal SC. The configuration setting pins PEWIDTH[5..0] of the chipset 280 set the PCI-Express bandwidth configuration in the chipset 280 according to the bandwidth configuration signal SC. As such, the chipset 280 determines that the I/O expansion card RC0 has one PCIEX16 interface card slot AD0.

When the I/O expansion card RC1 is plugged into the I/O expansion slot IOU1, the configuration message generator CM2 of the I/O expansion card RC1 generates a high voltage level bandwidth configuration message SM1 such that the MOSFET Q1 is turned on and the drain voltage of the MOSFET Q1 is in a low level. The adjustment circuit 450 outputs the adjusted digital code DG (digital code “110011” at this time) as a bandwidth configuration signal SC. The configuration setting pins PEWIDTH[5..0] of the chipset 280 set the PCI-Express bandwidth configuration in the chipset 280 according to the bandwidth configuration signal SC. As such, the chipset 280 determines that the I/O expansion card RC1 has two PCIEX8 interface card slots AD1, AD2.

While only one bit of the bandwidth configuration message SM1 is adjusted in the present embodiment, it should be understood that multiple MOSFETs or other components, circuits having the same function can be employed to adjust multiple bits of the bandwidth configuration message SM1 in alternative embodiments, which is not repeated herein.

In the embodiment described above, the configuration setting circuit 270 is used to transmit the bandwidth configuration message SM1 to the configuration setting pins PEWIDTH[5..0] of the chipset 280. A second embodiment will be described below with reference to FIG. 5A in which the configuration setting circuit 270 includes a complex programmable logic device (CPLD) 501. The CPLD 501 is coupled to the configuration setting pins PEWIDTH[5..0] of the chipset 280 and the I/O expansion slot IOU1. By being programmed in advance, the CPLD 501 can generate a corresponding digital code DG′ according to the bandwidth configuration message SM1 and the digital code DG′ is transmitted to the configuration setting pins PEWIDTH[5..0] of the chipset 280 to set the internal PCI-Express bandwidth configuration in the chipset 280. For example, when the configuration message generator 230 outputs a bandwidth configuration message SM1 of “01”, the CPLD 501 correspondingly outputs a digital code DG′ of “110011” to the configuration setting pins PEWIDTH[5..0]. When the configuration message generator 230 outputs a bandwidth configuration message SM1 of “02”, the CPLD 501 correspondingly outputs a digital code DG′ of “111011” to the configuration setting pins PEWIDTH[5..0].

A third embodiment will be described below with reference to FIG. 5B in which the configuration setting circuit 270 includes an encoding circuit 502. The encoding circuit 502 is coupled to the configuration setting pins PEWIDTH[5..0] of the chipset 280 and the I/O expansion slot IOU1. The encoding circuit 502 encodes the bandwidth configuration message SM1 to generate a corresponding digital code DG′. The digital code DG′ is transmitted to the configuration setting pins PEWIDTH[5..0] of the chipset 280 to set the internal PCI-Express bandwidth configuration in the chipset 280.

A fourth embodiment will be described with reference to FIG. 5C in which the configuration setting circuit 270 includes a micro processor 503. The micro processor 503 is coupled to the configuration setting pins PEWIDTH[5..0] of the chipset 280 and the I/O expansion slot IOU1. The micro processor 503 includes a mapping table therein. The micro processor 503 looks up a digital code DG′ corresponding to the bandwidth configuration message SM1 in the mapping table and transmits the digital code DG′ to the configuration setting pins PEWIDTH[5..0] of the chipset 280 to set the internal PCI-Express bandwidth configuration in the chipset 280.

In the first embodiment of the present invention described above, as shown in Table 1, the I/O expansion slot IOU1 consists of sixteen differential lines evenly allocated into four ports (i.e., Port7˜Prot10). As such, each port has four differential lines and bandwidth configuration settings of the I/O expansion slot IOU1 are achieved by various combinations of the four ports. The I/O expansion slot IOU1 has five bandwidth configuration settings as shown in Table 2. The I/O expansion slot IOU1 needs three selection bits as indicated by the bandwidth configuration message SM1[2..0]. The I/O expansion card 210 plugged into the I/O expansion slot IOU1 can generate a corresponding bandwidth configuration signal SM1[2..0] based on its bandwidth configuration requirement and transmit the bandwidth configuration signal SM1[2..0] to the configuration setting circuit 270 through the I/O expansion slot IOU1.

TABLE 2
Bandwidth Configuration Settings Table For I/O Expansion Slot IOU1
IOU1
Port7Port8Port9Port10
X4x4x4x4SM1 [2 . . . 0]
X4x4x4x4000
X8x4x4001
X4x4x8010
X8x8011
x16100

As shown in Table 3, the I/O expansion slot IOU0 consists of sixteen differential lines evenly allocated into four ports (i.e., Port3˜Prot6). As such, each port has four differential lines and bandwidth configuration settings of the I/O expansion slot IOU0 are achieved by various combinations of the four ports. The I/O expansion slot IOU0 has five bandwidth configuration settings as shown in Table 3. The I/O expansion slot IOU0 needs three selection bits as indicated by the bandwidth configuration message SM0[2..0].

TABLE 3
Bandwidth Configuration Settings Table For I/O Expansion Slot IOU0
IOU0
Port3Port4Port5Port6
x4x4x4x4SM0 [2 . . . 0]
x4x4x4x4000
x8x4x4001
x4x4X8010
x8X8011
X16100

As shown in Table 4, the I/O expansion slot IOU2 consists of four differential lines evenly allocated into two ports (i.e., Port1˜Prot2). As such, each port has two differential lines and bandwidth configuration settings of the I/O expansion slot IOU2 are achieved by various combinations of the two ports. The I/O expansion slot IOU2 has two bandwidth configuration settings as shown in Table 4. The I/O expansion slot IOU2 needs one selection bit as indicated by the bandwidth configuration message SM2[0]. In the present embodiment, the I/O expansion slots IOU0 and IOU2 can be configured in the similar way as described above with respect to the I/O expansion slots IOU1 and therefore explanation thereof is not repeated herein.

TABLE 4
Bandwidth Configuration Settings Table For I/O Expansion Slot IOU2
IOU2
Port1Port2
x2X2SM2 [0]
x2X20
x41

The configuration setting circuit 270 generates a corresponding bandwidth configuration signal SC (referring to Table 1) according to the bandwidth configuration message SM2[0] of the I/O Expansion Slot IOU2 (referring to Table 4), according to the bandwidth configuration message SM1[2..0] of the I/O Expansion Slot IOU1 (referring to Table 2), and/or according to the bandwidth configuration message SM0[2..0] of the I/O Expansion Slot IOU0 (referring to Table 3). The bandwidth configuration signal SC is transmitted to the configuration setting pins PEWIDTH[5..0] of the chipset 280 to set the internal interface-card-bandwidth configuration in the chipset 280. Those skilled in the art will appreciate that the configuration setting circuit 270 can be implemented as one of a CPLD 501, an encoding circuit 502 and a micro processor 503 upon reading the description of the embodiments above.

It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.